Collapsible crane



March 18, 1969 P. DURAND 3,433,368

GOLLAPSIBLE CRANE Filed Dec. 26, 1967 Sheet of '7 (Q-@OF} WW ,{///7/ y T/ IMVEA/T l? A- 712? QRMEZJ Sheet 5 of 7 Filed Dec. 26, 1967 March 18, 1969 P. DURAND COLLAPSIBLE CRANE Sheet Filed Dec. 26, 1967 March 18, 1969 P. DU RAND 3,433,368

COLLAPS IBLE CRANE Filed Dec. 26, 1967 Sheet 5 of 7 I/VYENTAR &3 $1M A TTJ RMEXJ March 18, 1969 P. DURAND 3,433,368

COLLAPSIBLE CRANE Filed Dec. 26, 1957 Sheet 6 of 7 vv-EN T' R B Y 1 v I VA 774 R ALE/J7 March 18, 1969 P. DURAND COLLAPSIBLE CRANE Sheet 7 of? Filed Dec. 26, 1967 I/VrENTa R m EMM l3 y a/ US. Cl. 212-46 Int. Cl. 1566b 23/68 6 Claims ABSTRACT OF THE DISCLOSURE A collapsible crane including superposed pivotally interconnected tower sections and a jib wherein the raising of the tower sections into vertical alignment is ensured by a winch acting on a tackle block inserted between the lower tower section and the frame to which the latter is pivotally secured. Said tackle block can be disconnected with reference to the frame and be connected with an auxiliary cable removably connected with the cable controlling the raising of the jib into a horizontal position and a collapse of the crane structure. The winch may thus control last-mentioned operations without unduly stressing the tower girders.

My invention has for its object an improved collapsible crane and more particularly a collapsible crane incorporating a pulley block which allows executing in succession the spreading out of the crane tower and the raising of the jib.

Cranes for the building industry are already known, which include tower sections and a jib which are pivotally interconnected, said crane being adapted to be brought from one position for which the crane is in its collapsed condition into an operative position for which the tower sections and jib are in their spread out condition. The French Patents 1,347,727 and 1,474,803 and also the German model of utility 1,825,633 describe such cranes. The spreading out starting from the first-mentioned or transportation position is generally performed by means of a tackle block which raises the tower sections while the jib is released with reference to the uppermost tower section and is brought into its horizontal operative position during the last stage of the crane-raising operation by the reaction of a cable of an unvarying length, one end of which is attached to the frame carrying the crane or to a superstructure rigid with said frame, while the other end of the cable is secured to a post or arm adapted to raise the jib. It has been found that during said last-mentioned stage, very large stresses may arise in the girders of the tower, chiefly in the case of a crane having a large hoisting capacity.

In order to cut out said drawback, and with a view to consequently reducing the weight of the framework of the crane, I provide a crane of the type considered, wherein the spreading out of the crane is performed in two successive stages, to wit: the raising of the tower sections and the setting of the jib in its horizontal position and, according to my invention, said crane carries a tackle block producing the desired erection of the crane; a number of pulleys of which serve as stationary or movable pulleys as required.

According to a particular feature of my invention, said tackle block may also serve, if desired, for the laying of ballast on the crane frame.

According to another advantageous feature of my invention, the pulley block can serve also if required, for furthering the folding up of the tower sections.

I will now proceed to describe, by way of example and in a non-limiting sense, a preferred embodiment of my invention as illustrated in the accompanying drawings, whereby a proper understanding of my invention and of its various features may be obtained. In said drawings:

FIG. 1 is a diagrammatic elevational view of my improved crane in its collapsed condition ready for transportation.

FIG. 2 is a diagrammatic elevational view of the same crane whereof the tower sections have been set into their operative positions.

FIG. 3 is a diagrammatic elevational view of said crane showing how the pulley block of the crane can serve for laying a ballasting block on the crane frame.

FIG. 4 is a diagrammatic elevational view of said crane during the jib-raising operation.

FIG. 5 is a diagrammatic elevational view of the same crane in its final operative position.

FIG. 6 is a further diagrammatic elevational view of the crane during the jib-folding back operation.

FIG. 7 is a diagrammatic elevational view of the crane during the collapsing of the tower sections.

FIGS. 8 and 9 are diagrammatic perspective views of two different positions of a modification of the tackle block.

Turning to FIGS. 1 to 7, which illustrate my improved crane at different stages of its erection and of its collapsing, said crane includes a movable frame 1 carrying a rotary platfrom 2 on which the lower tower section 4 is adapted to revolve round a horizontal pivot 3, said lower section 4 rests on the frame 1 through an abutment 5 when the crane is in its inoperative collapsed condition, as illustrated in FIG. 1. The upper section 6 of the tower is secured to the lower section 4 through the upper part of the latter as provided by a pivot 7 acting as a hinge, said upper section bearing, for the inoperative transportation condition of the crane on an abutment 8 rigid with the superstructure 9 carried by the platform 2. The upper end of the tower section 4 and the lower end of the tower section 6 are provided with automatic locking means illustrated diagrammatically at 10a and 10b, wherethrough the sections 4 and 6 are constrained to remain in vertical alignment as soon as the erection of the tower has been executed. The crane jib 11 is pivotally secured at its inner end 12 to the upper end of the tower section 6 and is provided near said inner end with a jib-raising post or arm 13 which may be removed during the transportation of the crane and to which is secured a cable 15 of an unvarying length (FIG. 2), the other end of said cable 15 being secured to a fitting 17. Said fitting 16 is provided with holes 17 and 18 (FIG. 3) which allow securing it selectively to a pivot 19 provided on the superstructure 9 and to an auxiliary cable 40 the part played by which will be disclosed hereinafter.

Two connecting rods 20 are arranged to either side of the tower sections, one of which connecting rods is shown in FIGS. 2 to 7. Said connecting rods are each pivotally secured at one of their ends (FIG. 2) to a horizontal pivot 21 on the superstructure 9, while the other ends 22 of said connecting rods are connected with the ends of the links such as 23 and 24 by means of straps for instance. These links 23 and 24 are pivotally secured respectively at their other ends to the lower tower section 4 at 25 and to the upper section 5 at 26. The lengths of the links 23 and 24 are different and their pivotal connections with the tower sections are defined by the kinematic conditions governing the tower raising and collapsing mechanism of the crane. The crane is also provided with a raising winch 27 actuating a tackle block 28 including pulleys 29 secured to the lower tower section 4 at a predetermined distance from the pivotal axis 3 and pulleys 30 carried by a fitting 31 secured removably to the superstructure 9 by means of a pivot or spindle adapted to be inserted in one of the holes 32a and 32b provided for this purpose in said fitting 31. The latter is also provided with attachment means 33 for the auxiliary cable 40, the part played by which will appear hereinafter as mentioned. Lastly, the superstructure 9 carries a guiding pulley 34 adapted to be engaged by said auxiliary cable.

The raising and folding of such a crane are performed as follows:

The crane being originally in its operative transportation condition illustrated in FIG. 1, that is with the fitting 31 secured to the superstructure 9 through the hole 32a, the operation of the winch 27 produces, through the agency of the tackle block 28 a tractional stress F1 and consequently a rocking of the lower tower section 4 round its carrier pivot 3. The upper tower section 6 secured to the section 4 as provided by the hinge or pivot 7 is urged upwardly together with the jib 11 carried by it, while it simultaneously assumes an angular movement round the hinge 7 under the bracing action of the reaction forces F2 and F3 exerted by the connecting rod and links 23 and 24. The force F2 urges in fact the section 6 and the jib 11 into a rocking motion round the pivot 7, while the force F3 the direction of which is at an angle with that of F2 urges into a vertical position the system constituted by the sections 4 and 6 and by the jib 11.

FIG. 2 illustrates the crane in its intermediate position at the end of the tower-raising stage, during which the tower sections are brought into vertical alignment. When said vertical alignment has been obtained, the sections 4 and 6 are secured together by the automatic locking means 104: and 10b.

It is then of advantage to proceed with the laying on the platform 2 of a block forming a balancing ballast through the means illustrated in FIG. 3. The balancing ballast 35 lying on the ground is pivotally secured to the platform 2 by means of horizontal spindles 36 extending through suitable fittings 37 and 38 which are welded respectively to the platform 2 and to the ballasting block 35. A further fitting 39 provided on the ballasting block is then connected with the fitting 31 of the tackle block through the agency of the auxiliary cable 40 after the latter has been fed round the guiding pulleys 34, care being taken to maintain said cable 40' in a tensioned condition. This being done, the fitting 31 is disconnected with reference to the superstructure 9, as provided by removing the spindle engaging the hole 32a. The winch 27 is then actuated again so as to produce through the agency of the pulley block 28 a pivotal movement of the ballasting block 35 round the pivot constituted by the spindles 36. When the ballasting block reaches the position illustrated in interrupted lines in FIG. 3, a securing lug 41 rigid with the ballasting block engages a stud '42 rigid with the superstructure 9. It is then suflicient to lock the parts 41 and 42 together so that the ballasting block may be securely held on the platform 2 and on the superstructure 9 carried by the latter. Of course, the positioning of the ballasting block may be performed in any other suitable manner different from that described, which should be merely considered as an advantageous possible manner of proceeding. It is thus possible to position the ballasting block by means of a removable pivotaLhoisting device such as a davit secured to the rear of the crane frame. For sake of clarity, the ballasting block has been omitted in FIGS. 4 to 7. The tower sections being now erected and the ballasting block positioned, it is possible to proceed with the raising of the job. To this end, the tackle block is loosened and a connection is provided between the fittings 31 and 16 through the auxiliary cable 40 which is caused to engage the guiding pulley 34. This being done, the winch 27 and tackle block 28 are actuated so as to tension the cables 40 and 15 which are thus interconnected and to thereby raise the jib 11 as provided by the torque produced by the force F1 (FIG. 4) and the lever arm constituted by the post 13. When the jib has reached its horizontal position, it is held fast in said position by securing the fitting 16 to the superstructure 9 by means of the pin or pivot 19. The crane has thus assumed its operative position (FIG. 5).

When it is desired to return the crane into its collapsed position, it is first necessary to lower the jib 11 and to this end it is sufiicient to disconnect the fitting 16 with reference to the superstructure and to loosen the tackle block 28 by releasing the winch 27 so that the cable 16- allows the jib 11 to drop until it forms an angle at of a few degrees with the alined tower sections; it is then possible to secure the tackle block fitting 31 to the superstructure 9 by inserting through the hole 32b of the fitting a pin or spindle to engage the part 9 (FIG. 6). As a matter of fact, it is necessary to produce for opening the hinge 7 with a view to folding the tower sections a torque F4D with reference to said hinge, which is larger than the torque F5d holding the tower sections in alignment. The excess value of the opening torque over the torque F5d is obtained by reason of the obliquity of the cable 15 and of its tensioning by the jib 11 forming an angle or with the tower axis. It is now sufficient to release the locking means 10a and 10b and to slightly slacken the tackle block so that the two sections of the tower are allowed to slightly rock round the hinge 7 in opposite directions, the lower section being no longer held in position by the tackle block 28 and this rocking movement continues until the tackle block has been thereby tensioned again (FIG. 7). A further gradual release of the tensioning of the tackle block ensures thereafter the complete collapse of the crane. During the collapsing movement, it should be remarked that the jib 11 engages gradually a position of rest over the upper tower section 6.

FIGS. 8 and 9 illustrate a modification of the tackle block which modification may be incorporated with my improved crane whenever a large speed reduction is required. This modification distinguishes from the precedingly disclosed tackle block through the fact that the auxiliary cable 40, instead of being secured to the fitting carrying the pulleys which are selectively stationary and movable, engages in succession a first pulley rigid with the superstructure carried by the crane frame, then over a pulley carried by the spindle carrying selectively stationary and movable pulleys and over a second pulley rigid with the superstructure, and is anchored to the crane frame. Thus, the modification includes the winch 27, two stationary pulleys 43 and 44 secured to the lower crane section, pulleys 45, 46, 47 carried by a fitting 48 removably secured to another fitting 50 by means of a pin or spindle inserted through one of the holes 49a or 4% provided for this purpose in the fitting 48. The fitting 50, on the other hand, is pivotally secured to the superstructure 9 by means of a spindle 51 carrying two further pulleys 52 and 53. The winch-controlled cable passes in succession over the pulley 43, the pulley 45, the pulley 44 and the pulley 47 before its anchoring in the tower section 4.

As to the auxiliary cable 40, in passes in succession over the pulleys 52, 46 and 53 and is secured at 54 to the crane frame.

FIG. 8 illustrates last-mentioned tackle block with the pulleys 45, 46 and 47 operating as stationary pulleys while FIG. 9 illustrates the same pulley block with the pulleys 45, 46 and 47 operating as movable pulleys. The passage of one condition to the other is obtained merely by removing the pin or spindle inserted through the holes 49a or 49b. The operation of this modification is exactly the same as that disclosed with reference to FIGS. 1 to 7, as concerns the erection and collapsing of the crane structure.

Obviously, the above description is given solely by way of example and many modifications may be brought thereto by resorting to technically equivalent means, without widening the scope of the invention as defined by the accompanying claims.

I claim:

.1. In a collapsible crane including a carrier frame, a lower tower section pivotally secured to said carrier frame, an upper tower section pivotally secured through its lower end to the upper end of the lower tower section and a jib pivotally secured to the upper end of the upper tower section, the provision of a control system comprising a winch, a tackle block including first pulley means carried by said lower tower section, second pulley means carried by fitting means, a main cable controlled by the winch and engaging said first and second pulley means, an auxiliary cable controlling the movements of an arm rigid with the jib, and means for securing selectively said fitting means to a member rigid with the carrier frame to ensure, upon operation of the winch, the shifting of the tower sections from a collapsed position into a vertically alined position, and to the auxiliary cable to ensure the shifting of the jib between its collapsed and raised positions.

2. A control system as claimed in claim 1, wherein said fitting means can be secured in two different positions to the member rigid with the carrier frame.

3. A control system as claimed in claim 1, wherein said auxiliary cable comprises means for securing it to a member rigid with the carrier frame.

4. A control system as claimed in claim 1, comprising furthermore a ballasting means pivotally secura'ble to the frame and adapted to be raised onto the later off a lower position, upon operation of the winch, said ballasting means being able to be connected to said fitting means through connecting means.

5. A control system as claimed in claim 1, comprising furthermore a guiding pulley carried by a member rigid with the frame, said auxiliary cable engaging said pulley and being secured to the fitting means before collapsing the tower sections whereby the tension of said auxiliary cable promotes the pivoting of the tower sections, one with respect to the other, upon slackening of the main cable.

6. A control system as claimed in claim 1, wherein said fitting means can be secured in two different positions to second fitting means pivotally mounted around an axis which is fixed on the frame and carries third pulley means, said auxiliary cable being anchored to the frame and operatively engaging at least one pulley of said second pulley means and said third pulley means.

References Cited UNITED STATES PATENTS EDWARD A. SROKA, Primary Examiner.

US. Cl. X.R. 212144, 49 

